OpenStack is one of the fastest growing open source projects in history. It is rapidly becoming the standard for open source, public and private clouds. Since its first release in 2010, there have been 12 major releases, with the thirteenth under development as of the writing of this book. OpenStack originally started with two projects, Object Storage (Swift) and Compute (Nova). This huge amount of commitment and contribution has led to the momentum that OpenStack enjoys today.
OpenStack has become very popular among companies and organizations because it allows them to provide public and private clouds to their employees, partners, customers, and constituents. In addition, the vibrant community around OpenStack allows its adopters to avoid lock in and gives them freedom to work with the technologies of their choice. As an open source project, those who adopt it have the freedom to work with the community and add functionalities and features as they see fit. This flexibility has enticed hundreds of organizations to join this community, many dedicating developers to the cause.
OpenStack is extremely powerful, but it is not without complexity. One of the side effects of its rapid growth and large community involvement is the fact that things often change quickly. New projects are added regularly, and along with those projects, come new functionalities. As the community finds better ways to implement things, it often necessitates change. As the projects begin to get more and more integrated, it becomes very important to understand how these projects flow and interrelate. While the growth of OpenStack has been rapid, the development of OpenStack talent has not kept pace. As a result, individuals with OpenStack skills are in high demand.
OpenStack requires operators with the ability to identify, isolate, and troubleshoot errors that might arise in the environment. Troubleshooting OpenStack is not always straightforward because the functionality of an OpenStack cloud is delivered by several different projects all working together under the OpenStack umbrella. In addition, the OpenStack projects are further augmented by external open source technologies. With OpenStack's power and flexibility comes the challenge of pinpointing the source of errors and problems. While this challenge is real, it is by no means insurmountable.
In this book, we will show you how to find success with OpenStack troubleshooting. We will introduce you to inside tips and a winning methodology to troubleshoot your OpenStack cluster. It is assumed that you are familiar with the basic Linux administration, cloud computing in general, and OpenStack in particular. We will walk you through a set of useful tools to troubleshoot OpenStack, and we will provide a step-by-step guide to address common problems in installation, performance, availability, and automation. We will focus on central OpenStack projects, including those providing compute, storage, and networking. By the time we reach the end of this book, you will be better prepared to tackle the OpenStack troubleshooting challenges that may come your way. You will have a better understanding of how OpenStack works under the hood, and this understanding, along with the tips and methodologies presented in this book, will make you an efficient and confident OpenStack troubleshooter.
In this chapter, we will cover the following topics:
- The project overview of OpenStack
- Basic troubleshooting methods and tools
- Installing packages
The more you understand about OpenStack, how it is organized and architected, the more successful you will be at troubleshooting it. In this section, we provide you with a strong foundation of understanding about OpenStack. Throughout the book, we will build on this foundation, going deeper into each project as we encounter them in future chapters. To start the journey, we will introduce you to some of the projects that are commonly deployed in an OpenStack cluster. It's worth pointing out that we won't cover every OpenStack project, but we will attempt to adequately cover each of the commonly deployed projects.
Keystone is the OpenStack Identity service. It is responsible for authentication and is involved in authorization for an OpenStack cluster. Keystone is also responsible for service discovery, allowing users to see which services are available in a cluster. A user-initiated request will typically flow through Keystone; so, learning to troubleshoot this service is a wise investment.
Glance is the OpenStack Image service. Glance is primarily responsible for image registration and storage. As an example, compute instances can be created based on machine images. These images are typically stored through and retrieved via Glance.
Neutron is the OpenStack Networking service. Networking is hard, and it is no different in OpenStack. Neutron is responsible for abstracting the network-related functionality in OpenStack. This is an area where many operators may run into trouble. Learning how to skillfully troubleshoot Neutron will serve you well as an OpenStack administrator.
Nova is the OpenStack Compute service. Nova provides compute instances in an OpenStack cloud. This is one of the largest OpenStack projects and one of the oldest. Nova is used heavily in an OpenStack cloud, and it is critical that troubleshooters understand this project, its concepts, components, and architecture.
Cinder is the project that provides block storage services for OpenStack. Cinder abstracts and provides access to several backend storage options. Compute instances will often receive their block storage via the Cinder service.
Swift is the OpenStack Object Storage service. Swift provides object-based storage, which is accessed via an API. Unlike Cinder, Swift does not expose block-level storage, but it does offer a system that allows you to store petabytes of data on a cluster that is built on commodity hardware.
The OpenStack Orchestration service is named Heat. Heat allows users to leverage a declarative template language to describe, build, and deploy OpenStack resources. It is designed to allow users to manage the entire life cycle of their cloud resources.
Ceilometer is the OpenStack Telemetry service, and it is responsible for collecting utilization measurements from physical and virtual resources in an OpenStack cloud.
The OpenStack dashboard is named Horizon. Horizon provides the graphical user interface for OpenStack. It relies on the OpenStack APIs to present much of this functionality. It is an extremely useful tool when troubleshooting the APIs or OpenStack functionality in general.
Oslo is the OpenStack project that contains the shared Python libraries that are leveraged across all projects. Examples of these include code that supports messaging, command-line programs, configuration, and logging.
One of the strengths of the OpenStack community is that it treats documentation as a first-class citizen. In the community, documentation is just as important as code. The documentation project is structured like the others and receives a good amount of exposure and attention.
In addition to the these projects, there are several other popular projects worth mentioning. These projects include the following:
While Nova typically handles the provisioning of virtual machines, with Ironic, users can provision physical hardware in a cloudy way. The Ironic driver allows you to deploy bare metal hardware in a similar fashion to the way you deploy virtual machines.
Magnum is a project designed to allow users to manage application containers in OpenStack. This allows container orchestration engines, such as Docker and Kubernetes, to be leveraged through OpenStack.
Trove is an OpenStack service that provides cloud databases. The Trove service supports the provisioning of both relational and non-relational databases.
Barbican is a service that facilitates the management, provisioning, and storage of secrets. Secrets include things such as passwords, encryption keys, and certificates.
Congress provides a policy as a service for OpenStack. The aim of the project is to provide a framework for regulatory compliance and governance across cloud services. Its responsibility is policy enforcement.
Designate provides DNS as a service. This service provides zone and record management as well as support for multiple nameservers.
These are just some of the many projects under the Big Tent of OpenStack. New projects with the promise of a new functionality are created regularly. As these projects gain more and more adoption, the chance that you will need to troubleshoot them increases.